Automatic timer



y 1943- J. EDELEN 2,441,402

AUTOMATIC TIMER Filed March 25, 1944 Patented May 11, 1948 AUTOMATICTIMER James L. Edelen, Kirkwood, Mo., assignor to Carter CarburetorCorporation, St. Louis, Mo., a corporation of Delaware Application March23, 1944, Serial No. 527,853

Claims. 1

This invention relates to timing devices and consists particularly in anovel apparatus of this type for use in connection with a fluid fiowmeasuring machine to operate a flow controlling valve.

Machines of this type have been used in calibrating and testingcarburetors for internal combustion engines. The operators of such flowmachines customarily, calculate with the aid of a watch, the quantity offuel consumed during a period of time. The flow from the measuringdevice is started and stopped manually so that the attention of theoperator is divided between the timing instrument, the shut-off valve,and the carburetor itself.

It is an object of the present invention to provide a timing devicewhich operates wholly automatically, once it is set in motion, to openthe flow controlling valve and hold it open for the exact time desired.

A more detailed object is to provide a timing device in which themechanism is initially set in motion by the operator, but thereafterperforms the timed operation and shuts itself oil wholly automatically.

These objects and other more detailed objects hereafter appearing areattained by the device illustrated in the accompanying drawing in which:

Fig. 1 is a diagrammatic view of a carburetor flow machine with thenovel timing device applied thereto.

Fig. 2 is a perspective view of the timing device on an enlarged scale.

Fig. 3 is a sectional view of the gasoline flow controlling valve. I

Fig. 4 is a similar view with the valve in a different position.

Fig. 5 is a view of a detail in Fig. 2 and is taken substantially online 55 of Fig. 2.

The flow machine illustrated in Fig. 1 comprises a suction pump I0operated by an electric motor H and connected by a pipe I! to a vacuumbox l3. A carburetor I4 is shown mounted on top of box 13. Thedepression in the box, which is effective to draw air and fueldownwardly through the carburetor barrel, is measured by a manometerassociated with a scale iii. A practical form of manometer for thispurpose is illustrated in my co-pending application, Serial No. 615,688,filed January 1, 1944. The carburetor is connected by a tube IT to anelevated constant level chamber 18 which, in turn, is connected by atube 19 either to a fuel pump or gravity fuel feed.

A T-fitting 20 is interposed in tube I1 and mounts a vertical burette2|. A barrel valve is mounted in T 20 and is controlled by an arm 26 towhich is connected the core 21 of a solenoid 28. A return spring 29constantly urges the valve to the normal position of Fig. 3.

The timing device is mounted on a substantial plate 30 having an anglebracket 3| projecting 'rearwardly therefrom. An electric motor 32,mounted on the front face of plate 30, has its shaft 33 projectingthrough the plate and rigidly attached to a driving cam 34. A shaft 35is journalled between plate 30 and bracket 3| parallel to the motorshaft and rotatably receives first and second control cams 3'6 and 31having alternate high and low peripheral surfaces, as shown.

Cam 31 has ratchet teeth 39 formed thereon adjacent a hand lever 40which is loosely received on shaft 35. Lever 40 carries a pivoted detent4i urged by its own weight against teeth 39 to form a ratchet. Lever 40and cam 31 are urged rightwardly by a coiled, compression spring 42compressed between bracket 3| and the lever. Teeth 43 on the abuttingfaces of cams 36 and 31 form a one-way, ratchet connection therebetween.

A set of ratchet teeth 45 are formed on the other control cam 36adjacentan angular lever 46 loosely received on shaft 35. A spring lip 41engages these teeth to prevent counterclockwise rotation of the cam.Lever 46 mounts a pivoted detent 48 yieldingly held in ratchetengagement with teeth 45 by a spring strip 49. A coiled spring 50 isconnected between a lug 5| on plate 30 and an extension 52 on lever 46for constantly urging this lever clockwise.

Lever 46 also has a finger 53 constantly urged against the periphery ofdriver cam 34 by spring 50. The contour of driver cam 34 is such thatduring one revolution thereof, from the position shown in Fig. 2, lever46 is rotated counterclockwise to cause pivoted detent 48 to clear oneof the teeth 45. Finger 53 is then dropped to the low point of cam 34 topermit spring 50 to rotate lever 46 and control cam 36, through teeth 45and detent 48, one step in the clockwise direction. By means of themeshing teeth 43, this motion of cam 36 is also transmitted to controlcam 31.

Mounted in bracket 3|, below cams 36 and 31, are cam followers 54 and 55which actuate switches 56 and 51, respectively, connected to andcontrolling solenoid 28 and motor 32. The electrical switch connectionsare conventional and, it is believed, will be clearly understood fromthe diagram in Fig. 1. These switches are held 3 normally open bysprings, diagrammatically shown at 58 and 59.

The contour of cam 36 is such that switch 55 controlled thereby isalternately closed and opened at successive rotational steps of the cam,each produced by one cycle of driving cam 34. The contour of cam 31 issuch that switch controlled" thereby is maintainedv closed during twosteps of rotation thereof, as produced by two cycles of drive cam 34,and then opened for one step.

This device operates as follows:

To initiate the timing operation, the operator rotates lever 40clockwise which, through detent 4| and teeth 39, rotates camST clockwiseone stepso as to close switch 51 and start motor 32. Thereupon, rotationof drive cam 34 operates lever 46.

and detent 48 to rotate cam 36 one step. Solenoid switch 56 is thenclosed, causing valve arm 2-6 tobe rotated counterclockwise and valve 25to be turned to the npositionsh'owninFig. 4. Liquid in burette 21 isthen fedithroughithe tube I! and the carburetor. Since the high. pointson cam 31 are relatively. wide, motor switch 51 is maintained closedfora secondcycle of driving cam" 34. At the end of this cycle, lever 45.and detent 48 are operated by. spring, 50 to-rotate cam 35 anotherstepandbring a low point thereon opposite solenoid: switch actuator 54and open this switch. Thereupon, solenoid: plunger 21 is released. andspring 29 returns-va1ve25to the position in Fig. 3 closing, theconnection between the burette and carburetor and opening the burettetoelevated fuel chamber l8.-f.or'refilling ofthe'burette; Coincidentally,or slightly thereafter, a low point on cam 31 moves opposite motorswitch actuator 55 so that switch 51 is opened and the motor is stopped.

Initiation of the-timing operation by lever 40, is effectedindependently of earns 36 and 34 because of spring-42-whichpermitsratchet teeth 43 to ride apart. Thedriving motor is maintained inoperation automatically for exactly one complete timing periodwhichzismeasured bytwo steps of cam 31; regardless'of the'stopping position ofdrive cam 34. Timing ofthe liquid fuel discharge from. the burette is,thus, effected with a minimum of attention fronrthe operator, who mayobserve the-functioning of thecarburetor or the manometer. Moreoventhetime element inhis calculation remains constant automatically.

The invention is particularly adapted for use with a portable flowmachinesuch as illustrated in my co-pending application mentioned above,but is adaptable to other timed operations where its inherent functionmay be advantageous.- The device may be modified in. various-respects aswill occur to those skilled in the art and-the exclusive useof allmodificationsas come within the scope of the appended claims iscontemplated.

I claim:

1. A control device-for a timed operation com.- prlsing'a driving membercapable of rotation at uniform speed, a pair of controls, respectively,for'a timed operation andsaid member, a pair of cams'and cam followers,respectively, for actuating said controls; means operatively connectingsaid driving member'andisaid cams for joint; step by step actuation of'said cams, and means to in-- dependently actuate one of 'said cams tostart said driving member; said last-mentioned cam being shaped tomaintain said driving member in operation between two succeeding stepsand to stop said driving member at the third step and the other cambeing shaped to actuate its control at each step to alternately startand stop the timed operation.

2. A timing device comprising a driving member capable of operation atuniform speed, first and second-cams and followers therefor forcontrolling, respectively, a timed operation and said driving member,means operatively connecting said member and said first cam for step bystep rotation of the latter by said member, a one-way, operativeconnection'between said cams for joint rotation thereof by said member,and means to independently. rotate said second cam, step by step,,saidsecond cam being shaped to start said driving member upon rotationthereof through one step from its normal stopping position and tomaintain said member in operation through the next step, and to stopsaid member at the third step, and saidfirst cam being shaped toalternately start and stop the timed operation at succeeding stepswhereby accurate timing of the controlled operation is obtained uponinitial actuation of said second cam.

3. A timing device as described in claim 2 in which said driving membercomprisesa cam having a one-way, ratchet connection to said firstcontrol cam arranged to rotate said first cam one step during each cycleof said member.

4. A timing device asdescribed in claim. Zlurther including manual meansto rotate said second control camindependentl of said first cam and saiddriving member to start thetiming cycle, said second cam being:automatically rotated thereafter by said driving member to stopthetiming cycle.

5. A timing control device comprising a motor capable of operation at auniform speed, a control switch therefona driven shaft, a first and asecond control cam rotatablev on said shaft, followers for said cams:for controlling, respectively, a timed operation and said switch, a stepby step, operative connection between said motor andsaid first cam, aone way operative connection be-- tween said first. and second camsforeffecting joint rotation-thereofinone direction by'said motor, andmanual means to rotate said second cam, independently, tostart saidmotor, said second cam being shaped to-close said switch during: twosucceeding steps of said shaft andv to. open said switch at thethirdsucceeding step, andlsaid first cam being shaped to alternatelystart,.stop, and restart the timed operation during succeeding stepswhereby a uniformly timed operation will be insured upon initial manualmovement of' said second cam.

JAMES L. EDELEN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS.

